Kinetic Oxidation Laws Of Boron Carbide In Dry And Wet Environments

Boron compounds e.g. boron carbide formulated as B4C are introduced in SiC matrix itself to further improve the oxidation resistance of ceramic matrix composites (CMC) under load at high temperatures with a view to applications in the aerospace field. In dry environments, at relatively low temperatures and below 1000 degrees C, the oxygen access into such a composite is limited by the formation of fluid oxide phases based on B2O3(1), sealing the matrix cracks.In contrast, under wet environments, B2O3(1) volatilization is important and responsible for an active oxidation regime. In such an environment at 600 degrees C, a limitation of the oxidation rate by a kinetic or a diffusion mechanism could be highlighted,Now, this database is accurate enough to allow the modeling of the oxidation along a matrix crack in these self-heating composites.